Abstract A pressure drop indicator for a braking system comprising two independent circuits, one of said circuits comprising a pressure limiter, said indicator comprising a body formed with a bore, a movable member slidably mounted in said bore and responsive to the pressure in both circuits, said movable member being adapted to co-act with a control element of an electric switch so as to close an electric signal circuit in case of fluid leakage in one of said circuits, said movable member comprising a first piston provided with a rod movable in a bore formed in the other or second piston, said second piston being adapted to co-act with said electric switch control element between two axial abutment positions, said piston providing at the ends of said bore in said body first and second chambers to which the feed lines of said first and second circuits are adapted to be connected, said second circuit comprising said pressure limiter, the pressure drop indicator being characterized in that the end of the rod of said first piston comprises a valve portion adapted to close a passsage hole formed in said second piston to provide a fluid passage between said second chamber and an auxiliary chamber for supplying fluid to the second circuit and by-pass said pressure limiter when a pressure drop takes place in said first circuit.
A pressure drop indicator for a braking system comprising two independent circuits, one of said circuits comprising a pressure limiter, said indicator comprising a body formed with a bore, a movable member slidably mounted in said bore and responsive to the pressure in both circuits, said movable member actuating a control element on an electric switch and closing an electric signal circuit in case of fluid leakage in one of said circuits, said movable member comprising a first piston provided with a rod movable in a bore formed in a second piston, said second piston further actuating said electric switch control element at two axial abutment positions of said second piston, said pistons providing at the ends of said bore in said body first and second chambers to which feed lines of said first and second circuits are connected, said second circuit comprising said pressure limiter, the pressure drop indicator being characterized in that the end of the rod said first piston comprises a valve means removably closing a passage hole formed in said second piston and providing a fluid passage between said second chamber, and an auxiliary chamber in said body for supplying fluid to the second circuit and by-pass said pressure limiter when a pressure drop takes place in said first circuit and a spring disposed between the adjacent faces of said first piston and said second piston for constantly urging the valve of said first piston rod away from said second piston passage hole.
Claim 2
Dependent Claim
247 words
A pressure drop indicator for a braking system comprising two independent circuits, one of said circuits comprising a pressure limiter, said indicator comprising a body formed with a bore, a movable member slidably mounted in said bore and responsive to the pressure in both circuits, said movable member actuating a control element on an electric switch and closing an electric signal circuit in case of fluid leakage in one of said circuits, said movable member comprising a first piston provided with a rod movable in a bore formed in a second piston, said second piston further actuating said electric switch control element at two axial abutment positions of said second piston, said pistons providing at the ends of said bore in said body first and second chambers to which feed lines of said first and second circuits are connected, said second circuit comprising said pressure limiter, the pressure drop indicator being characterized in that the end of the rod said first piston comprises a valve means removably closing a passage hole formed in said second piston and providing a fluid passage between said second chamber, and an auxiliary chamber in said body for supplying fluid to the second circuit and by-pass said pressure limiter when a pressure drop takes place in said first circuit and a spring disposed between the adjacent faces of said first piston and said second piston for constantly urging the valve of said first piston rod away from said second piston passage hole.